Fins 101; Priscacara
We use here a Priscacara to illustrate some of the details of fin morphology used to identify particular species. The number of spines and fin soft rays can frequently be used to differentiate closely related species.
The data in the table below is taken from Grande 1980 and illustrates how the fin ray counts can be used to differentiate the two Priscacara species. Note that the fin rays (the soft rays) may be split and should not be counted as two rays, this is particularly true of the last (rearmost) ray.
| P. serrata | P. liops | |
| Dorsal fin rays | usually 10 spines, 9 or 10 rays |
usually 10 spines, 12 or 13 rays |
| Dorsal pterygiophores | usually 19-20 | usually 21-22 |
| Anal fin rays | usually 3 spines, 8 or 9 rays |
usually 3 spines, 10-12 rays |
| Pelvic fin spine | stout, as thick as dorsal spines | thinner than serrata |